Feed problems after new install

I’m having problems with newly installed wordpress blogs on 2 seperate sites.

I recently made a website and installed wordpress on it, but after the site admin entered 1 post, we became aware that after a short period of time, the text kept being cut short. I also realised then that the feed wasn’t working. I tried everything I could think of but have no idea what is causing the problems.

I also installed wordpress onto a currently unused site of mine to see if the problem was just a one off, but the same problem came up again. This time, it’s installed in the root directory at https://wwweuphonynetwork.com/
Default theme, no plugins installed but yet the feed still won’t work.

I’m a bit of a wordpress noob, but I have it installed on another of my websites which is hosted on the same server, and works fine on this site.

Thanks for any help!